Sari Mäntynen, University of Helsinki

Authors: Sari Mäntynen [1], Meri M. Salomaa [1], Sarianna Helander [1], Silja Rapinoja [1] and Minna M. Poranen [1] Affiliations: [1] Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland

Epidemiology, Evolution, and Diversity

Over half a century has passed since the discovery of Pseudomonas phage phi6, the first dsRNA bacteriophage to be isolated and the first member of the Cystoviridae virus family. The complete nucleotide sequences of 14 dsRNA phage isolates are currently available and the isolates have been officially classified into the Cystoviridae family by the International Committee on Taxonomy of Viruses. We have recently isolated and characterized novel dsRNA phages from environmental samples collected in Finland, demonstrating that this virus type is more abundant and widespread than previously acknowledged. Our results show that dsRNA phages can infect various Pseudomonas syringae pathovars that cause diseases in important crop plants resulting in severe economic losses worldwide. Interestingly, the sensitivity of Pseudomonas strains to dsRNA phage infections can be controlled by mobile genetic elements. We explore the potential of dsRNA phages for plant disease control both in vitro and in greenhouse under controlled conditions. Consequently, this study provides novel information on the quadro-trophic relationships between mobile genetic elements, dsRNA phages, host bacteria and plants, furthering our understanding of complex microbial communities.